Process of manufacturing cellulose products.



ATENT mes.

MAX FREMERY AND JOHANNES URBAN, OF OBERBR'UCH', 'lERll/IAN'Y'.

PROCESS OF MANUFACTURING CELLULOSE PRODUCTS.

SPECIFICATION forming part of Letters Patent No. 650,715, dated. May 29,1900.

Application filed February 6, 1900.

T0 to whmn it may concern:

Be it known that we, MAX FREMERY, a subject of the King of Prussia,Emperor of Germany, and JOHANNES URBAN, a subject of the Emperor ofAustria-Hungary, both residing at Oberbruch, near Aachen, in the GermanEmpire, have invented certain new and useful Improvements in Processesof Manufacturing Cellulose Products; and we do hereby declare thefollowingto be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

Our invention relates to new and useful improvements in the manufactureof glossy threads, fibers, films, and other similar products obtainedfrom cellulose dissolved in cellulose solvents; and it consistsespecially in improvements in and relating to the drying of suchcellulose products.

In order to obtain more solid or firmer and more glossy celluloseproducts from cellulose which is separated or precipitated from solventsthereof-such as, for example, solution of chlorid of zinc or of cupraammonium or of any other solvent-or from hydrocellulose or the varioushydrates of cellulose or amyloid. These cellulose products after theirmanufacture are dried at a temperature not exceedin g about 40centigrade. This process, which, although an invention of ours, is notthe subject of this application, can be promoted by employing a vacuumor a current of air. These cellulose products such as threads, fibers,films, and the like*- are kept under tension by being wound on rollersor spools while they are subjected to this drying process, thecylindrical rollers everywhere acting uniformly in opposition to thenatural contraction which takes place, while the gradual re moval ofwater produces a uniform tension of the thread, fiber, or the likethroughout, which is necessary to obtain a high gloss and closesimilarity to silk. I

In practical experiments with the process referred to we have observedthat the drying takes place in two stages or phases. A first part of thewater contained in the threads evaporates fairly rapidly. The greaterpart, however, only evaporates very slowly. We concluded from this thatthis larger part of the Serial No. 4,259. (No specimens.)

contained water is in a fixed, possibly chemical, combination with thecellulose. This slowly-evaporating part of the water may therefore becalled here water of hydration of the cellulose. Further experimentswere therefore undertaken with the View of rem dering the water ofhydration at least more loose in its combination with the cellulose, inorder, possibly, by these means to evaporate this firmly-united quantityof water contained in the cellulose products more rapidly than or asrapidly as the first part of the watercoutained therein. The desiredresult cannot be attained by a simple elevation of the temper ature ofthe drying-chamber, since a brown ing or discoloration of the cellulosethread will then take place and the gloss and firmness thereof will bedeteriorated. In. these experiments we discovered or invented thefollowing process, forming the subject of our present application:

The cellulose threads, fibers, films, or the like obtained in anysuitable or known manner from cellulose solution are while freshlyproduced in a more or less gelatinous condition. According to thepresent invention these products are subjected to the action of water(liquid or vaporous) at an elevated temperature (about 80 centigrade toabout 100 centigrade) and are then dried at a comparatively-lowtemperature,not exceeding 40 centigrade.

The process may be performed in the manner which we will now explain byway of example. The rollers on which the said more or less gelatinouscellulose products are wound during their manufacture are dipped for ashort time in hot water (at a temperature of from 80 to 100 centigrade)or brought into contact with a current of steam-that is to say, therollers on which the manufactured cellulose products are wound aresubjected to the action of a high temperature (from 80 to 100centigrade) in the presence of water, (liquid or gaseous.) By thisaction the whole of the water is now easily removed by drying. Afterthis treatment the cellulose threads, films, or the like on the rollersare dried by subjecting these rollers or spools to a moderate heat, (upto about 40 centigrade,) preferably in suitable drying chambers, whereinthis drying may be promoted by employing a vacuum or an acceleratedchange of the air, (attained by ventilation.)

By employing the preliminary treatment above mentioned (action of a hightemperature in the presence of water) for this drying process only abouta quarter of the time heretigrade, substantially as and for the purposeset forth.

2. The process of imparting a glossy appearance and acomparatively-great strength to cellulose products obtained fromcellulose solutions, such process consisting in winding up thesecellulose articles while freshly pro duced, subjecting these celluloseproducts while wound up to the action of water at an elevatedtemperature from about 60 to about 100 centigrade and then drying thesame at a comparatively-low temperature not exceeding about 40centigrade, substantially as and for the purpose set forth.

In testimony whereof we afiix our signatures in presence of twowitnesses.

M. FREMERY. JOHANNES URBAN. \Vitnesses:

E. M. BRUNDAGE, O. E. BRUNDAGE.

